The size of brain ventricles is especially relevant in some brain diseases such as epilepsy, schizophrenia and other neurodegenerative diseases. Many studies have been conducted to assess the brain ventricles. To the best of our knowledge, however, there is no fourth, third and lateral ventricles volume study evaluating the efficiency and accuracy of point-counting and planimetry methods of the Cavalieri principle in the literature. In the current study, we estimated the volume of intracerebral ventricles in normal subjects using stereological methods. The volumes of fourth, third and lateral ventricle were estimated in 14 young Turkish volunteers ( 7 males and 7 females), aged between 18 and 36 years and free of any neurological symptoms and signs, using serial magnetic resonance imaging (MRI). Volumes of intracerebral ventricles were determined on MRIs using the point-counting and planimetry methods. The mean results of the point-counting method were 14.7 +/- 4.2, 8.7 +/- 3.0 and 131.8 +/- 33.1 mm(3) for the fourth, third and lateral ventricles, respectively. The mean results of the planimetry method were 15.4 +/- 3.4, 8.6 +/- 3.5 and 153.7 +/- 34.6 mm(3) for the fourth, third and lateral ventricles, respectively. Ventricle volumes obtained by the two different methods were not statistically different ( p > 0.05) and they correlated well with each other. Good agreement was found between results obtained with the point-counting and planimetry techniques. The findings of the present study using stereological methods could provide data for the evaluation of normal and pathological volumes of intracerebral ventricles.